As a commercialized desiccant dehumidifier, a dehumidifying device as disclosed in, for example, Patent Literature 1 has been conventionally known. A dehumidifying device 100 disclosed in Patent Literature 1 employs a moisture-absorbing material such as zeolite or silica gel. The moisture-absorbing material is applied to a filter member 101 which has a honeycomb shape and which has air permeability (see (a) and (b) of FIG. 12).
This type of moisture-absorbing material absorbs moisture in air in a case where a temperature of the moisture-absorbing material is equal to or lower than a given temperature, and releases absorbed moisture as water vapor in a case where the temperature of the moisture-absorbing material is higher than the given temperature. Therefore, the dehumidifying device 100, employing the moisture-absorbing material having such a property, has the following mechanism. That is, a fan 102 causes air in a room to pass through the filter member 101 so that the filter member 101 (i.e., the moisture-absorbing material) absorbs moisture in the air. On the other hand, in a case where absorbed moisture is taken out from the filter member 101, a rotating section 104 rotates the filter member 101 through 180 degrees so that a surface of the filter member 101 which surface has absorbed moisture faces a heater 103. The heater 103 then causes high-temperature wind to pass through the surface of the filter member 101, which surface has absorbed the moisture, so that the filter member 101 is heated up. This ultimately causes the moisture contained in the filter member 101 to be released as water vapor. Thereafter, a heat exchanger 105 causes high-temperature air, containing the water vapor, to be cooled down. This causes the moisture to be taken out in a tank 106. The dehumidifying device 100 thus dehumidifies air in a room.
As a conventional moisture-absorbing material, a dehumidifying and water-absorbing sheet as disclosed in, for example, Patent Literature 2 has been known. A dehumidifying and water-absorbing sheet disclosed in Patent Literature 2 includes (i) a gel sheet having a water-absorbing property which varies depending on a relationship between a temperature of the gel sheet and a temperature sensitive point and (ii) a sheet heater integrally adhered to the gel sheet. The gel sheet exhibits a high water-absorbing property in a case where the temperature of the gel sheet is equal to or lower than the temperature sensitive point, and exhibits a low water-absorbing property in a case where the temperature of the gel sheet is equal to or higher than the temperature sensitive point. Therefore, in a case where the gel sheet is heated to a temperature equal to or higher than the temperature sensitive point by the sheet heater, the gel sheet releases absorbed water and accordingly becomes able to absorb water again. This allows the gel sheet to be reused.